Xotx5b, a new member of the Otx gene family, may be involved in anterior and eye development in Xenopus laevis

Vignali, Robert; Colombetti, Sara; Lupo, Giuseppe; Zhang, Wenge; Stachel, Scott E.; Harland, Richard M.; Barsacchi, Giuseppina

doi:10.1016/s0925-4773(00)00367-1

Cited by 48 publications

(65 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All of these experiments indicate that the regulation of retinaspecific genes share some conserved features between vertebrates. Taken together with phylogenetic studies and analysis of expression patterns, these experiments provide convincing evidence that Otx5 is involved in rhodopsin regulation in a manner similar to mammalian Crx (28,29,34,48,49). Experiments in this report show this conservation functionally for the first time using a non-mammalian promoter.…”

Section: Discussionsupporting

confidence: 64%

“…Furthermore, Nrl has been shown to bind to Crx (33), and with Crx, can synergistically activate expression of the rhodopsin promoter (24). We show here that Xenopus XOtx5 (34,35) and XL-maf (36) are the functional Xenopus counterparts of mammalian Crx and Nrl.…”

mentioning

confidence: 70%

“…The pCS2-XOtx5b full-length expression construct was obtained from A. Viczian and has been described previously (34). The XL-maf coding region was produced by RT-PCR (see below) and the resulting PCR product was cloned into pBluescript using the engineered BamHI and EcoRI sites.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Conserved Transcriptional Activators of the Xenopus Rhodopsin Gene

Whitaker

Knox

2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

Vertebrate rhodopsin promoters exhibit striking sequence identities proximal to the initiation site, suggesting that conserved transcription factors regulate rhodopsin expression in these animals. We identify and characterize two transcriptional activators of the Xenopus rhodopsin gene: homologs of the mammalian Crx and Nrl transcription factors, XOtx5 and XL-Nrl (originally named XL-maf), respectively. XOtx5 stimulated transcription ϳ10-fold in human 293 cells co-transfected with a plasmid containing the rhodopsin promoter (؊508 to ؉41) upstream of luciferase, similar to the ϳ6-fold stimulation with human Crx. XL-Nrl stimulated transcription ϳ27-fold in mammalian 293 cells co-transfected with the rhodopsin luciferase reporter, slightly more than the ϳ17-fold stimulation with Nrl. Together, the Xenopus transcription factors synergistically activated the rhodopsin promoter (ϳ140-fold), as well as in combination with mammalian homologs. Deletion of the Nrl-response element, TGCTGA, eliminated the synergistic activation by both mammalian and Xenopus transcription factors. Deletion of the conserved ATTA sequences (Ret-1 or BAT-1), binding sites for Crx, did not significantly decrease activation by Crx/XOtx5. However, there was increased activation by Nrl/XL-Nrl and an increased synergy when the Ret-1 site was disrupted. These results illustrate conservation of mechanisms of retinal gene expression among vertebrates. In transgenic tadpoles, XOtx5 and XL-Nrl directed premature and ectopic expression from the Xenopus rhodopsin promoter-GFP transgene. Furthermore, activation of the endogenous rhodopsin gene was also observed in some animals, showing that XOtx5 and XL-Nrl can activate the promoter in native chromatin environment.Photoreceptors are highly specialized cells with complex structures that permit efficient light absorption, high signal transduction amplification, rapid kinetics, and adaptation over a range of light intensities (1). Phototransduction requires the coordinated expression of many genes, including the visual pigments that absorb light, enzymes involved in the cGMP cascade, ion channels plus multiple regulatory and structural proteins. It has been estimated using serial analysis of gene expression that ϳ4% of the genes expressed in the retina encode phototransduction proteins (2). Many of these genes are quite conserved in vertebrates. Moreover, programs of eye development share many conserved features in the animal kingdom (3, 4). Even in such distantly related species as Drosophila and humans, similar transcription factors are involved in development and expression of retina-specific genes (5, 6), although the evolutionary significance is not yet settled (5, 7, 8). Often, proteins involved in growth and differentiation of the eye from one species can substitute for homologs in distantly related species (4, 7). This conservation also extends to the cis-acting elements in proximal promoters of retinal genes. Promoters have exhibited at least partial functionality between mammals and lower vertebrate...

show abstract

Section: Discussionsupporting

confidence: 64%

mentioning

confidence: 70%

See 1 more Smart Citation

Conserved Transcriptional Activators of the Xenopus Rhodopsin Gene

Whitaker

Knox

2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…To help clarify how FGF signaling affects organizer formation, we analyzed expression of the organizer genes goosecoid (gsc), chordin, xnr3, and noggin (Cho et al, 1991;Smith and Harland, 1992;Sasai et al, 1995;Smith et al, 1995) as well as otx2 and otx5 (Lamb et al, 1993;Vignali et al, 2000), which are expressed in the dorsal mesendoderm prior to expression in the anterior neural plate. Embryos were analyzed at the early gastrula stage.…”

Section: Fgf Signaling Is Essential For Establishment Of Paraxial Mesmentioning

confidence: 99%

“…Anti-sense RNA probes were made for the following transcripts: xbra (Smith et al, 1991); myoD (Hopwood et al, 1989); sox2 (Grammer et al, 2000); otx2 (Lamb et al, 1993); otx5 (Vignali et al, 2000); hoxB9 (Sharpe et al, 1987); gsc (Cho et al, 1991); myf5 (Hopwood et al, 1991); noggin (Smith and Harland, 1992); chordin (Sasai et al, 1995); xnr3 ; sox17 (Hudson et al, 1997); eomes (Ryan et al, 1996); VegT (Stennard et al, 1996); edd (Sasai et al, 1996); FGF4 (Isaacs et al, 1992); FGF8 (Fletcher et al, 2006).…”

Section: Whole Mount Rna In Situ Hybridizationmentioning

confidence: 99%

The role of FGF signaling in the establishment and maintenance of mesodermal gene expression in Xenopus

Fletcher

Harland

2008

Developmental Dynamics

View full text Add to dashboard Cite

FGF signaling is important for the formation of mesoderm in vertebrates, and when it is perturbed in Xenopus, most trunk and tail mesoderm fails to form. Here we have further dissected the activities of FGF in patterning the embryo by addressing its inductive and maintenance roles. We show that FGF signaling is necessary for the establishment of xbra expression in addition to its well-characterized role in maintaining xbra expression. The role of FGF signaling in organizer formation is not clear in Xenopus. We find that FGF signaling is essential for the initial specification of paraxial mesoderm but not for activation of several pan-mesodermal and most organizer genes; however, early FGF signaling is necessary for the maintenance of organizer gene expression into the neurula stage. Inhibition of FGF signaling prevents VegT activation of specific mesodermal transcripts. These findings illuminate how FGF signaling contributes to the establishment of distinct types of mesoderm.

show abstract

Eye Development

Bene¹,

Wittbrodt²

2005

Cell Signaling and Growth Factors in Development

View full text Add to dashboard Cite

Xotx5b, a new member of the Otx gene family, may be involved in anterior and eye development in Xenopus laevis

Cited by 48 publications

References 44 publications

Conserved Transcriptional Activators of the Xenopus Rhodopsin Gene

Conserved Transcriptional Activators of the Xenopus Rhodopsin Gene

The role of FGF signaling in the establishment and maintenance of mesodermal gene expression in Xenopus

Eye Development

Contact Info

Product

Resources

About